From the interest on substituted triazines as materials for various resin and fine chemicals, various synthetic methods and derivatives thereof have been developed.
As the synthetic method, for example, reported are various novel synthetic methods for catalytically obtaining N-substituted triazine derivatives using industrial starting materials, such as the synthetic method by amino exchange reaction between melamine and a corresponding amine derivative [as described in U.S. Pat. No. 4,618,676 (1986), U.S. Pat. No. 4,668,785 (1987), etc.], the method for obtaining an N-substituted triazine derivative using a 1,3,5-triazine derivative, typically represented by melamine, as a starting material and an alcohol [WO95/03287 (corresponding to JP-A Hei8-27128)], the method for obtaining N-substituted triazine derivatives using an aldehyde and a ketone [WO95/30662 (corresponding to JP-A Hei8-193071)], and the method for obtaining N-substituted triazine derivatives using an olefin (JP-A Hei8-27125), proposed by the present inventors. Also, reported are the method for obtaining N-substituted triazine derivatives proposed by the present inventors by reacting a 1,3,5-triazine derivative as a starting material with an alcohol in the presence of a metal catalyst and hydrogen [as described in WO97/24338 (corresponding to JP-A Hei10-231291), etc.]
The methods described in U.S. Pat. Nos. 4,618,676 (1986) and 4,668,785 (1987) and the like perform reactions at elevated temperatures using acid catalysts and are extremely excellent methods for introducing general alkyl groups or a hydroxyethyl group. However, as for amines, generally those that are available at low costs are limited so that there is a limitation on the starting material for introducing various substituents according to this method, resulting in that only limited compounds can be industrially supplied at low costs.
The above-described production methods by the present inventors are methods using starting materials that can be available at low costs on an industrial scale. In particular, those methods using alcohols are recommendable methods from the viewpoints of the kind, price, stability and the like of the starting material. However, sometimes a high temperature and a long time are required depending on the reactivity of the substance and there may occur problems, such as induction of side reactions that will not be observed usually and low productivity.
Therefore, it has now been desired to develop a method for modifying melamine derivatives that can use alcohols that can be available at low costs on an industrial scale and is further improved industrially.